This invention relates generally to telecommunication networks in which subscribers can select how incoming calls are to be handled. The invention, more specifically, relates to network messages which are used to define how incoming calls are processed in the telecommunication network.
Telecommunication networks provide users with the ability to determine how incoming calls (call requests) are to be handled or processed. For example, a company in the United States may provide its customers with toll-free "800" telephone numbers as a convenience in servicing their requests for sales, service, and product information. Teams of agents employed by the company may be provided at different geographic locations to receive and process the customer's calls. However, the company may desire to have such incoming calls handled by different agent teams, depending upon the time of day and/or the day of the week, or type of call. An explanation of the processing of such calls by the telecommunication network is provided below.
FIG. 1 illustrates a known telecommunication network which includes central office switches 10 and 12 which support a plurality of subscribers using cutover premises equipment 14 and 16, respectively. The central office switches 10 and 12 are coupled by trunk lines 18 and 20 to toll switches 22 and 24, respectively. The toll switches 22 and 24 are connected together by a trunk line 26 and are connected to other central office switches and/or other toll switches by trunk lines 28. It will be apparent to those skilled in the art that a substantial number of central office switches and toll switches may be interconnected to provide a communication system within a geographic area such as within the continental United States. In the illustrative example, the central office switches and the toll switches may comprise 5ESS.RTM. switches and 4ESS.TM. switches which are available from AT&T Corp. The illustrative customer premises equipment 14 and 16 may comprise analog or digital telephone sets as well as other communication equipment including terminals, computers linked by modems, and other forms of video or other information systems.
A signaling network 32 which may follow the signaling system 7 (SS7) standard is connected by communication channels 30 to the central office and toll switches. It is well known that the signaling network will typically include a plurality of communication nodes such as signal transfer points (STP) which exist to relay (transmit) network messages between the switches in order to control the processing and routing of calls. A service control point (SCP) node 34 is connected by communication channel 36 with the signaling network 32. The SCP node, also known as a network control point (NCP), provides the intelligence which provides the processing logic and stores the subscriber provided data which defines how incoming call requests are to be handled. As used herein, the handling of a call means resulting actions based on an incoming call request and may include the providing of a variety of services including, but not limited to, determining a routing destination of the associated call. A service management system (SMS) 38 is connected by communication channel 40 to the SCP node 34. The SMS 38 is utilized to provision the subscriber data and logic processing definitions stored in SCP node 34. A computer workstation 42 is coupled by communication channel 44 to SMS 38 and provides a system administrator or service provisioning agent with an interface to the SMS 38 and provides the mechanism by which the call handling requirements of a customer are entered into the SCP node. The SMS 38 provides a communication interface to transmit control information and data entered by a system provisioning agent using station 42 to the SCP node 34 such as over a X.25 communication link 40. The SCP node 34 may comprise a No. 2 direct services dialed (2DSD) node available from AT&T Corp. The service management system 38 may comprise an Intelligent Network Service Management System (INSMS) available from AT&T Corp.
The SCP node 34 contains service logic which receives call processing messages from signaling network 32, processes such messages, and generates and transmits network messages transmitted to signaling network 32 which are routed to the appropriate switch to provide control instructions and data concerning the handling of a corresponding call. Such messages may comply with a known protocol such as the transaction capabilities application part (TCAP) as associated with the SS7 network. The SCP node 34 also contains a database which stores data associated with specific customers which is accessed by the signal processing routines in order to generate the network messages which will provide the instructions to the switches to provide the processing and routing of calls as desired by the called party.
FIG. 2 illustrates a block diagram of an exemplary SCP node 34. It contains a microprocessing unit 46, read-only memory (ROM) 48, random access memory (RAM) 50, and a nonvolatile data storage device 52 which may comprise a hard drive or other type of nonvolatile data storage. These elements are coupled to and support the operation of microprocessing unit 46. An input/output interface 54 is also coupled to microprocessing unit 46 and provides a communications interface for signals being transmitted and received on communication lines 36 and 40. Program control instructions which control the operation of microprocessing unit 46 may be stored in ROM 48, RAM 50, and storage device 52. As is known to those skilled in the art, such processing steps and operating routines may be accessed and utilized in accordance with the overall processing instructions being executed by microprocessing unit 46. The nonvolatile storage device 52 may also be utilized to store customer provided data related to different users and hence, provides the information needed to make call handling decisions. For example, a customer may alter the destination of a received 800 call request, depending upon the time of day so that calls placed at the beginning of a business day are placed to agents located in the Eastern United States and so that calls placed at the end of the business day are routed to operating agents located in the Western United States. The routing of calls based on time-of-day parameters is controlled by storing customer data in the database of the SCP node indicating the times during which incoming calls are to be routed to the agent destinations in the Eastern and Western United States. Thus, call destinations are determined by the SCP node 34 in response to a network message corresponding to a call request.
The microprocessing unit 46 of SCP node 34 includes a visually depicted region of compiled steps 56 which represents program instructions which have been compiled for direct execution by the microprocessing unit as is known to those skilled in the art. Such processing steps may include the receipt and decoding of network messages received from the signaling network 32, locating and retrieving user data stored in the database in storage device 52, and the generation and transmission of network messages having a predefined format to signaling network 32. Similarly, received instructions from the SMS 38 are decoded and acted upon by the compiled steps 56 to place new user data in an appropriate memory location. The compiled processes are efficient in that these are directly executed by the microprocessing unit 46, but are also restrictive in that changes to the compiled steps usually require the changes to be made in a separate associated source program, compiled, and then loaded into the microprocessing unit 46 in place of the previously stored compiled steps. Such a reloading operation creates a time in which microprocessing unit 46 is unavailable for processing incoming messages or generating outgoing messages due to the requirement for the reloading of an active compiled program.
In the known implementation of SCP node 34, the format of network messages to be sent to signaling network 32 are defined by the compiled steps, but the data which may be included within such a formatted message is retrieved from the database in storage device 52. This provides customers with the ability to change the destination of a call, depending upon time of day or day of week or other conditions. However, it is not possible in the known system as shown in FIGS. 1 and 2 to maintain SCP node 34 in operation and make a change to the format of a network message to be sent to the signaling network 32. Thus, a service disruption will be required if a customer request requires a change to the format of the network messages exchanged between the SCP node 34 and the switches. This service disruption is caused by the requirement to load a new compiled program having the capability to provide the new formatting corresponding to the new service.
For example, assume that a customer desires that all calls be routed to agents at a Chicago, Ill. destination, but when all lines to the agents are busy, additional calls are to be rerouted to agents at a destination in Atlanta, Georgia. Since the determination of whether a number is busy or not will be determined by the associated terminating (destination) switch, alternative number information would be required to be routed as part of a network message sent by the SCP node 34 to the first destination switch (Chicago). Such a message would require the transmitting of a first destination number and a second alternate destination number which would be utilized in the event of a busy condition at the first destination number. Assuming that a format capable of sending two potential destination numbers along with an indication of the parameter which would cause the selection of the alternate destination number (busy state) is not an established format in compiled steps 56 of microprocessing unit 46, a new compiled program containing this capability would be required to be loaded and would require a service disruption. Thus, there exists a need for an improved method for providing greater flexibility in allowing a network operator to implement service changes by generating control messages with different formats without requiring a service disruption in the telecommunication network.